Attention 64 experts! Can anyone explain to me which gunsight/crosshair is used to aim the 30's? In most of the shots where 30cal is being fired, the crosshair in the centre doesn't track the line of fire. Does the gunner have another sighting system?

On November 2nd, 2009, the Afghan National Police station for the Marawara district of Kunar province, Afghanistan, was attacked by insurgent forces using small arms, RPG's and mortars. Intercepted radio comms showed that the force spoke a mix of Pashto, Arabic, and other languages not native to the area.
Due to the restrictive rules of engagement, and the risk averse environment fostered by our command, we were not allowed to provide artillery fires to Afghan security forces on the ground, even though they had contacted us begging for help.
In spite of the face that we had live video feed, real time translation of intercepted enemy radio traffic, and confirmation of enemy movement and disposition from the ANP, we were not allowed to use our 155mm Howizters to provide protective fires to aid the ANP on the ground because we were told we didn't have positive ID of enemy forces.
As a small unit leader trained in mounted and dismounted combat and maneuver, I was denied permission to lead a ground quick reaction force to aid the Afghans and/or engage the enemy forces.
The results were the majority of the ANP fled, the insurgent set fire to the OP overwatching the police station, the ANP district chief who stayed and fought was taken outside of the compound by the enemy and shot in the head (he ended up miraculously surviving), the police station was ransacked and looted, and the enemy escaped largely intact.
The only reaction from our forces was to send a ground QRF that took over an hour to respond from a location significantly further away than our base, and a pair of OH-58D Kiowas conducted a few gun runs in the vicinity of the escaping enemy forces.
credits carabinero1979

On August 5, 2012, terrorists in Egypt's Sinai Peninsula stormed an Egyptian military base, killed more than 15 Egyptian soldiers and stole two vehicles. The two vehicles then headed toward Israel. Once one of the vehicles was inside Israeli territory, the Israel Air Force targeted it.
Egypt claims that 35 terrorists took part in the ambush.
The bodies of four terrorists were found on the Israeli side of the border and three others on the Egyptian side of the fence. Israel returned the bodies to Egyptian custody early Monday evening.